Bar joist



Feb. 3, 1931. T. A. LUCY 1,791,278

BAR JOIST Filed Feb. 2. 1928 Iii. 1 Hz 15 I I P;

Patented Feb. 3, 1931 PATENT OFFICE THOMAS A. LUCY OF BIRMINGHAM, UGTS COMPANY,

ALABAMA, ASSIGNOR '10 INGALLS STEEL PROD- OF BIRMINGHAM, ALABAMA BAR 3018']! Application filed February 2, 1928. Serial No. 251,277.

Another object is to provide such a joist in which the 'oints are secured mechanically and then wel ed.

Another object is to provide such a joist with improved means for anchoring the same in lace. Another object is to provide improved means for securing the lath thereto. 1 Another object is to provide a positive anchorage between the concrete slab and the top of the truss or joist.

Another object is to provide a means of preventing direct contact between the ceiling plaster and the bottom of the truss.

Further objects will appear from the following description, taken in connection with the accompanying drawing, in which- Figure 1 is a side view of part of a bar joist embodying this invention;

Figure 2 is an enlarged section on line 2-2 of Figure 1;

Figure 3 is a plan view of the end of the joist, showing means for anchoring the same to its support;

Figure 4 is a side elevation of Figure 3;

Figure 5 is a view similar to Figure 3, showing another embodiment of this invention; and

Figure 6 is a side elevation of Figure 5.

Referring to the accompanying drawing, 1 designates an upper chord member, which may be constructed of a pair of rods of bar iron laid substantially parallel to one another. The lower chord member 2 is constructed of a similar pair of rods, running parallel throughout the greater part of their length, but bent upwardly out of their normal plane at the ends, as shown at 3. The end portions 3 approach to within a short distance of the upper chord member and then proceed parallel thereto, as seen in Figurge 1. Both upper and lower chord memhere are secured by welding or otherwise to a gusset plate 4, which is placed between the rods of each pair and welded thereto. Similarl secured to the ends of the joist at right ang es to the gusset plate 4 is a bearing plate 5. This plate and the gusset plate 4 may be formed integrally so as to have a T-shaped cross-section.

A web member 6 is constructed of bar iron and bent into angular form, having oppositely directed loops, as illustrated in Figure 1. This web member is placed between the rods of the upper and lower chord members and positioned so that the loops project beyond said chord members. The pins 7 are then passed through the projecting loops so as to bear against the outside of each chord member. These joints are then secured by welding the webs and the pins to the chord members. This renders the joints mechanically secure without welding, and the additional welding then insures additional strength. The projecting loops at the top chord projecting into the concrete slab, form anchors which fasten the top chord effectively to the concrete slab.

At the ends of the joist, the bearing plate 5 has made integral therewith, either by welding thereto, as shown in Figures 3 and 4, or by cutting therefrom, as shown in Figures 5 and 6, or fixed thereto by other means, anchoring members 8. The members 8 are so positioned as to project in opposite directions. When the joist is placed upon its support, such as a girder 9, or a wall 10, the ends of the members 8 may be bent downwardly, as shown in Figures 4 and 6, so as to prevent the joist slipping from its support and to hold it securely in place.

The lower chord 2 has secured thereto, by wiring or otherwise, a channel member 11, which provides a furring member. The channel is so placed as to cover the projecting ends or loops of the web member 6 and to provide a straight edge along the bottom of the lower chord, to which the ceiling lath 12 may be attached in any suitable manner. This channel serves to keep the plaster ceiling away from the bottom chord permitting the chord bars to be surrounded by air, securing eifective insulation against heat should the ceiling plaster be subjected to a fire. The furring member 11 is not bentto follow the lower chord 2, but extends beyond the bend of the lower chord in the normal plane thereof, as shown at 13, so as to provide a support for the lath 12 clear to the end of the joist. The upper lath 14, which supports the floor slab of the story above, is simply cut to permit the protruding ends of the web member to pass therethrough, as shown at1"5.

It will be seen, therefore, that this invention provides a joist of improved strength and stability. The pins 7 will maintain the web member in place and take up the stresses therein, and even if the weld at the joint should fail. A double strength joint is thus provided. lhe projection of the web member below the lower chord is covered by the furring strip, so that a smooth and even edge is provided for attachment of the ceiling lath l2 and its supporting rods 16.

The ends of the joist rest upon broad bearing plates, which are securely welded to the joist and which have anchoring members integral with the bearing plate and, therefore, with the joist itself, by which it is secured to its supports. It will be appreciated that by this construction the joist is very securely fixed to the girders 9 of the building framework. A considerable number of these joists, necessary to support a floor being anchored in this way to the frame of the building, provide means for stiffening and strengthening that framework so as to resist side or torsional strains or stresses tending to warp the framework. The use of these joists will, therefore, add strength to the entire structure.

It is obvious that various changes may be made, within the scope of the appended claims, in the details of construction without departing from the spirit of this invention; it is, therefore, to be understood that this invention is not limited to the specific details shown and described.

Having thus described the invention, what is claimed is:

1. A bar joist having upper and lower chord members formed of parallel bars, a web member bent to form oppositely directed loops positioned between the bars of said chord members and extending therebeyond, pins passing through said loops and bearing against the outside of said chord members. a bearing plate secured to the bars of the lower chord at the end of the joist so as to directly support the tension in said lower chord, and an anchoring member formed integrally with said bearing plate and bendable to secure the joist in place.

2. A bar joist having upper and lower chord members formed of parallel bars, a web member bent to form oppositely directed loops positioned between the bars of said meters chord members and extending therebeyond, pins passing through said loops and bearing against the outside of said chord members, a bearing plate secured to the bars of the lower chord at the end of the joists so as to directly support the tension in said lower chord, and anchoring members formed i11- tegrally with said bearing plate to extend in opposite directions and bendable to secure the joist in place.

3. A bar joist having a lower chord member formed of parallel bars, a web member secured thereto by a pin passing through said web member and bearing against the lower sides of said bars, and a furring member along said chord below said pin.

4. A bar joist having a lower chord member formed of parallel bars, a web member projecting below said chord member and secured thereto by a pin passing through said web member and bearing against said chord member, and a furring member along said chord member and covering the projecting portion of said web.

5. A bar joist having a lower chord member bent out of its normal plane at its end, a web member projecting below said chord member and secured thereto by a pin passing through said web member and bearing against said chord member, and a channelled furring member secured along said chord member and covering the projecting portion of said web.

6. A bar joist having a lower chord member bent out of its normal plane at its end, a web member projecting below said chord member and secured thereto by a pin assing through said web member and earing against said chord member, and a channelled furring member secured along said chord member covering the projecting portion of said web and extending in the normal plane of said chord member beyond the bend thereof.

7 A bar joist having its lower chord formed of parallel bars bent upwardly and provided with a plate adapted to bear on a support, said plate having oppositely extendin g elements adapted to take over the support edges in order to anchor the joist thereon.

8. A bar joist having upper and lower chord members, and a furring member extending along and slightly spaced from said chord adapted to separate said chord from the plastered ceiling so as to provide an insulating air space around said chord.

9. A bar joist having upper and lower chord members formed of parallel bars, a web member bent to form oppositely directed loops positioned between the bars of said chord members and extending therebeyond, pins passing through said loops and secured to the outside of said bars, said lower chord member being bent upwardly at the ends and provided with a bearing plate, and a furring and beyond the bend thereof and positioned to cover the projecting portions of said web member.

10. A bar joist havin upper and lower chord members formed 0 parallel bars, a web member bent to form oppositely directed loops positioned between the bars of said chord members and extending therebeyond, and pins passing thru said loops so as to bear against the outside of said chord members and secured in place by welding.

11. A bar joist having upper and lower chord members formed of parallel bars, a web member bent to form oppositely directed loops positioned between the bars of said chord members and extending therebeyond, pins passing thru said loops so asto bear against the outside of said chord members and secured in place by welding, a bearing plate secured to the end of said lower chord member and an anchor member formed integrally with said plate and bendable to secure said joist in place.

In testimony whereof I aflixmy signature this 1st day of December, 1927.

THOMAS A. LUCY. l 

